Unexpected reason more planes are taking off late these days
Updated . First published
If your flight gets delayed because of a massive thunderstorm or windy weather, it’s easy to understand why. But what about when you’re stuck waiting for takeoff, but it’s calm and clear-skied outside?
When the weather is extremely hot – like the heatwave that Europe is currently experiencing – it is harder for planes to take off.
Heatwaves can cause flight delays. iStock
This is because the air is thinner, which means jet engines have to generate more thrust to actually get off the ground, Ross Aimer, a retired United Airlines captain and CEO of Aero Consulting Experts, told the Associated Press.
It’s a common occurrence in places like the Middle East, but as climate change worsens and temperatures rise, researchers predict it will become more of a widespread issue.
Pilots make specific calculations before take-off, based on the plane’s weight, airport elevation and outside temperature.
If these calculations show that the plane can’t safely depart, the airline might need to reduce cargo, or offload fuel or passengers, leading to delays.
In July, passengers were offered compensation to voluntarily give up their seats on an American Airlines flight out of Las Vegas, when temperatures hit 47 degrees Celsius.
“There is a science behind all this,” Ross the pilot said. “You can’t deny the science of flight and what it takes for an airplane to operate.”
Sometimes, pilots simply have to wait for temperatures to drop before they can take off, as removing weight isn’t enough. “At some point, the numbers just don’t make sense,” Aimer said. “You could roll down a runway as long as you want, and you still can’t take off.”
Planes are more likely to get delayed as temperatures rise. iStock
Airports are hot places
Even if it feels like it’s not getting that much hotter, don’t forget that airports tend to record higher temperatures than the street outside your house.
They’re big expanses of heat-absorbing concrete, with no greenery or shade, and constant heat waste being expelled from airplanes, ground vehicles and air conditioning systems.
Also, airports with shorter runways are more likely to face delays due to hot weather. Planes need room to build enough speed for takeoff, and in a heatwave, some airports’ runways simply aren’t long enough.
Airports generate a lot of heat. iStock
So what does this mean for the average traveller?
Researchers found in a 2017 study that by 2050, flights departing during the hottest part of the day will have to restrict weight by up to 30 per cent, if greenhouse gas emissions continued to rise.
Another, more recent study, found that planes taking off from four European airports would have to reduce the weight equivalent of 10 passengers per flight by 2065 in order to continue safely taking off.
